Oil slick retaining barrier



FIG. 1 is a perspective view of a oil slick retaining barrier showing mynew design;

FIG. 2 is a front view of one repeating unit thereof;

FIG. 3 is a right side view of one repeating unit thereof;

FIG. 4 is a top view thereof; and,

FIG. 5 is a bottom view thereof.

The broken line showing of an oil slick retaining barrier is forillustrative purposes only and forms no part of the claimed design.

The ornamental design for an oil slick retaining barrier, as shown anddescribed.